Sir you are having lots many question.
It would be better if we have a phone consultation so that we can solve all your queries.
To answer some of your queries:
You can take single registration for multiple business in same state.
GST rate for restaurant is 5% and you cant take ITC for same so no need of bills of vegetable etc for GST purpose.
Hope you find the information helpful if you do please rate it 5 and provide your valuable feedback for my improvement.
Thank you.